From: Steven Rostedt <rostedt@goodmis.org>
To: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Cc: linux-trace-devel@vger.kernel.org, Yordan Karadzhov <y.karadz@gmail.com>
Subject: Re: [PATCH 0/2] KernelShark2.0: Use libtracefs APIs to access tracefs
Date: Fri, 6 Mar 2020 17:34:11 -0500 [thread overview]
Message-ID: <20200306173411.783cccd0@gandalf.local.home> (raw)
In-Reply-To: <20200306151356.4bbeef14@gandalf.local.home>
On Fri, 6 Mar 2020 15:13:56 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:
> On Fri, 6 Mar 2020 11:29:00 +0200
> "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
>
> > From: "Tzvetomir (VMware) Stoyanov" <tz.stoyanov@gmail.com>
> >
> > The tracefs library provides APIs for accessing files from tracefs.
> > The library is part of trace-cmd, it is installed as part of trace-cmd
> > installation. KernelShark uses some of those APIs and must be linked with
> > the library
> >
> > Tzvetomir (VMware) Stoyanov (2):
> > KernelShark2.0: Link KernelShark to libtracefs
> > KernelShark2.0: Use libtracefs APIs to access tracefs
> >
>
> I added these patches to the latest kernelshark-2.0 and it still doesn't
> work for me. I did a little debugging, and noticed that it fails while
> reading the guest trace.dat file with:
>
> plugin "kvm_combo" failed to initialize on stream /tmp/trace-host-Fedora21.
>
> It seems to require that the guest trace.dat file has kvm events?
>
> Note, as I build my guest kernel with a make localmodconfig, which disables
> all modules that are not necessary to boot the box, there is no kvm events
> there. I can see why the host may need them, but not the guest. I'll
> rebuild my guest kernel with kvm events and see if that solves this (but
> that shouldn't be the case).
>
Just confirmed it. If I add kvm events to the guest, it synchronizes
automatically. Thus, it's a bug to expect the guest to have kvm events, as
there's no reason for them to do so.
-- Steve
next prev parent reply other threads:[~2020-03-06 22:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-06 9:29 [PATCH 0/2] KernelShark2.0: Use libtracefs APIs to access tracefs Tzvetomir Stoyanov (VMware)
2020-03-06 9:29 ` [PATCH 1/2] KernelShark2.0: Link KernelShark to libtracefs Tzvetomir Stoyanov (VMware)
2020-03-06 9:29 ` [PATCH 2/2] KernelShark2.0: Use libtracefs APIs to access tracefs Tzvetomir Stoyanov (VMware)
2020-03-06 20:13 ` [PATCH 0/2] " Steven Rostedt
2020-03-06 22:34 ` Steven Rostedt [this message]
2020-03-09 9:17 ` Yordan Karadzhov (VMware)
2020-03-09 15:44 ` Steven Rostedt
2020-03-09 16:30 ` Steven Rostedt
2020-03-09 9:10 ` Yordan Karadzhov (VMware)
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